[jlbutler81]

I've read the instructions on inspecting and replacing the chain when the hole in the tensioner is showing and motofaction's numbers put the length at 21.5mm or 0.850 to the hole. I came across a forum post of a member replacing his because he measured about 0.850 between the guide and the tensioner and you can see the hole. Mine is at 0.810 but is not quite at the hole yet. That users showed that the new chain put his tensioner to guide at about 0.6.

My donor bike and motor shows 9k on odometer, but I'm guessing the latter part of this motor's life as having been rather rough. Doing some rough math that means that my chain is 70% stretched? Which doesn't make sense if it's only 9k on motor and people expect them to last 30-40k miles. Maybe my cam chain had a rough life? Bad oil/flow etc. Too many cold starts followed by heavy driving...who knows.

My question is should I just roll with this cam chain or is it worthwhile swapping out? And is my opinion that it's towards the end of its life correct? I'm tired and maybe not thinking great. Chain alone is just $60 or so and I for sure don't want to be in this engine again in 10k miles. It'd seem worthwhile to do.

The post I reference:

Cx650 cam chain auto tensioner - tips & pics

I could not find anything on the cx650 cam chain tensioner in the quick reference list, So I thought I’d create this thread for future reference. Below is a picture of the engine with rear case off. The chain is at the end of its life. The tensioner is all the way out and there is not any slack...

www.cx500forum.com

His cam chain:

Mine, no hole but it's just to the inside of the tensioner body

 

[reclinedrelic]

My question is should I just roll with this cam chain or is it worthwhile swapping out?

If the engine is out of the frame now is a good time to do the maintenance even if you could get a bit more life from the present chain. Also a good time for water pump seal, stator and starter clutch.
The automatic tensioners are hard to find and they do break when the chain gets loose.

 

[jlbutler81]

If the engine is out of the frame now is a good time to do the maintenance even if you could get a bit more life from the present chain. Also a good time for water pump seal, stator and starter clutch.
The automatic tensioners are hard to find and they do break when the chain gets loose.

Hard to find and expensive, saw one on ebay for $250.

I'm doing the quad bypass thing but checking to make sure the motor's worth putting cash into first before buying parts. I had another thread going on that process, but for some reason thought a cam chain specific thread was better...probably should have left it all one thread.

I was sorta looking for reassurance that my idea of replacement wasn't dumb. But also any opinions on why a chain at 9k miles would be this bad. I can still see cross hatching in the cylinders so I didn't think this bike could have more miles than that. I had read somewhere that some bikes up north when started and driven without getting warm have a tendency to be very hard on cam chains but I can't recall if that was this CX500 forum or another.

 

[CXPHREAK]

Replace the chain. The spring coils have a lot of spacing, indicating the chain needs replacing.

 

[Sidecar Bob]

I had read somewhere that some bikes up north when started and driven without getting warm have a tendency to be very hard on cam chains but I can't recall if that was this CX500 forum or another.

My CX650E based sidecar outfit (currently with GL500 engine) has been mostly used in the cold half of the year here in Southern Ontario.That may seem like "up north" to you (a lot of people would laugh at that), but it did get cold enough for a few weeks most winters that I had to block the air to most of the rad for it to get close to warmed up during my 25 minute commute.
Thinking about it, I probably did go through camchains faster in the 650 engines I had in the bike previously but more like 45,000 Km, nowhere near as fast as 9000 miles.

Your 650 engine is about 38 years old, which is a long time for a bike. Who knows what it has been through or whether the odometer matched the engine. Heck, someone could have done the top end without touching the chain and replaced a speedometer that started to make noise.